1. Field of the Invention
The present invention relates to a bicycle pedal having a pedal body rotatably supported through bearings on a pedal shaft attached to a crank arm.
2. Description of the Related Art
A known example of bicycle pedals as noted above is disclosed in Japanese Utility Model Publication No. 1990-44630. In the known construction, the pedal shaft includes a distal portion having a smaller diameter than a proximal portion attached to the crank arm. A pair of ball bearings are mounted between the pedal body and the small diameter distal portion of the pedal shaft.
In the prior construction, since the pedal shaft is supported in a cantilever mode, the proximal portion of the pedal shaft is formed to have a large diameter to secure sufficient strength against a strong bending moment. The distal portion of the pedal shaft is free from a strong bending moment, and may therefore have a small diameter for accommodating the pair of ball bearings axially spaced from each other. With the pedal body supported through the ball bearings mounted on the small diameter portion, the prior construction avoids the pedal having an excessive thickness as a whole.
According to this prior construction, the pedal body is rotatably supported through only the pair of ball bearings. The pedal body, which is trodden directly by the cyclist's foot, and the pedal shaft are in point contact with the bearing balls. Consequently, the load of the treading force concentrates on positions of the point contact. Such positions tend to wear quickly, to impair durability of the pedal construction. The wear may result in displacement of the balls axially of the pedal shaft, whereby chattering occurs between the pedal shaft and pedal body to obstruct a smooth pedaling action.